The present invention relates generally to radiated sensitivity tests and more particularly to radiated sensitivity tests for mobile terminals using Global System for Mobile communication (GSM) technology.
Mobile terminal manufacturers typically test and certify the over-the air performance of a new mobile terminal design before making the mobile terminal available to the consumer market. Such tests are typically performed according to certification standards defined by one or more established review boards, such as the Personal Communication Services (PCS) Type Certification Review Board (PTCRB), the GSM Certification Forum (GSF), and/or the Cellular Telecommunications and Internet Association (CTIA).
An exemplary certification standard is the CTIA Method of Measurement for Radiated RF Power and Receiver Performance, referred to herein as the CTIA receiver standard. The CTIA receiver standard, among other things, defines radiated sensitivity requirements and test procedures for mobile terminals that use Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), and/or GSM communication protocols.
According to the current CTIA receiver standard, the test system is required to obtain 144 GSM radiated sensitivity measurements for each of a high, a medium, and a low frequency channel of a frequency band of interest, such as the 1900 MHz or 850 MHz frequency bands, to fully evaluate the GSM radiated sensitivity of the mobile terminal in a specific mobile terminal configuration. These measured sensitivities correspond to 72 different mobile terminal orientations, where each orientation provides a vertical and a horizontal sensitivity measurement. Further, the CTIA receiver standard requires that these tests be repeated for each of a free-space, a left-ear, and a right-ear mobile terminal configuration. Therefore, for a single-band mobile terminal, the CTIA receiver standard requires 144×9=1,296 sensitivity measurements. Assuming that it takes an average of 90 seconds to perform each sensitivity measurement, testing the GSM radiated sensitivity for a single-band mobile terminal takes approximately 32 hours. For dual-band and triple-band mobile terminals, this time increases to approximately 65 hours and 97 hours, respectively. Due to these test times, the radiated sensitivity certification tests may be prohibitively expensive.
Because the final certification tests are time consuming and expensive, manufacturers often perform preliminary tests in-house to identify and correct any potential problems before the final test and certification process begins. While these preliminary tests are often subsets of the final tests, such preliminary tests may still be time consuming and expensive. This is especially true if the mobile terminal design goes through multiple iterations, causing the preliminary tests to be repeated for each iteration. As an example, assume that a manufacturer performs GSM radiated sensitivity tests for three different prototypes of a dual-band mobile terminal before the mobile terminal is ready for final test and certification. In this example, using the time estimates discussed above, the manufacturer has to invest approximately 195 hours of in-house test time just to perform the preliminary radiated sensitivity tests. The manufacturer then has to invest another 65 hours to perform the final GSM radiated sensitivity certification tests. There is a need for a method and apparatus that provides comparable test results in less time, and therefore, at a lower cost.